Have these on my tower..looking to pump more power through them..I currently have a clarion 300w marine amp..running them...what is the max power I can put through them?...also since they are a couple years old now...about 2002-should I look into replacing the speakers...they have had a good life..not really abused..but now at the point with surfing and all that I would like a little more from them...has anyone done this in these style of speaker cans? ALSO-sub upgrade or box style for X9 prostar 209?